The National Institute for Clinical Excellence is examining endovascular closure of atrial septal defect and will publish guidance on its safety and efficacy to the NHS in England, Wales and Scotland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about endovascular closure of atrial septal defect.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the preliminary recommendation
• the identification of factual inaccuracies
• additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows:

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 22 June 2004

Target date for publication of guidance: September 2004

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

Current evidence on the safety and efficacy of endovascular closure of atrial septal defect appears adequate to support the use of this procedure provided that the normal arrangements are in place for consent, audit and clinical governance.

The procedure should only be performed in units where cardiac surgery is available.

All patients who have undergone the procedure should be entered on to the UK Central Cardiac Audit Database (UKCCAD).

An atrial septal defect is the persistence of a hold in the wall (septum) between the right atrium and left atrium of the heart. The foramen ovale usually closes spontaneously after birth; an atrial septal defect is present when this closure does not occur. In the most common type, an ostium secundum atrial septal defect, the septum between the atria fails to form properly during foetal development, resulting in a permanent hole. An atrial septal defect allows blood to flow from the left atrium to the right atrium, so increasing the flow of blood to the lungs. This is known as a shunt. Patients with atrial septal defects are usually asymptomatic through infancy and childhood. Symptoms such as exertional dyspnoea, fatigue, palpitations and syncope can occur and increasing age carries an increasing risk of stroke. Some patients may develop congestive heart failure.

Not all atrial septal defects require treatment, but it is generally agreed that larger defects and those associated with either symptoms or significant enlargement of the heart should be closed electively. Atrial septal defects requiring surgery are relatively rare. Conventional surgery for atrial septal defect is performed through an incision in the front of the chest. After establishing cardiopulmonary bypass, the right atrium is opened to gain access to the interatrial septum. The defect is then repaired using a patch or stitches. People usually stay in hospital for several days after the operation.

Endovascular closure of an atrial septal defect involves making a small incision in the groin to introduce a guidewire and delivery sheath into the femoral vein. An occluder device is then introduced through the delivery sheath on a semi-rigid cable and expanded within the atrial septal defect to close it. Echocardiography and fluoroscopic guidance are used to determine the size and position of the defect and to place the occluder device. A balloon may be used to measure the diameter of the defect. People can usually go home the next day. Small residual shunts after the procedure often resolve as endothelial tissue grows over and around the device. The claimed advantages compared with open surgery are shorter hospital stay, earlier return to normal activities and fewer complications.

Three non-randomised controlled studies reported successful closure rates immediately after the endovascular procedure of 96% (423/442), 98% (60/61) and 97% (28/29) compared with rates of 100% (154/154), 98% (60/61) and 100% (64/64), respectively, for conventional surgery. A large case series of 3460 patients reported that 97% (3301/3391) of atrial septal defects were successfully closed immediately after the procedure. Of the 4% (147/3460) of patients followed up for 2 years in this study, all maintained successful closure. A further case series reported that 1% (4/314) of patients had a significant residual shunt immediately after the procedure and 93% (99/107) of patients had a successful closure 1 year after the procedure. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors noted that a small proportion of patients may be left with a residual shunt.

The reported complication rates were low. The most commonly reported complications included malposition of device requiring endovascular or surgical retrieval 1% (6/417) to 5% (16/334); arrhythmia 0.4% (2/459) to 5% (3/61); embolisation of the device 0.4% (14/3460) to 4% (14/334); thrombus formation 0.4% (1/258) to 3% (1/37); brachial plexus injury 3% (1/39); right iliac vein dissection 0.6% (1/159); stroke 0.1% (5/3460) to 0.3% (1/334); cardiac tamponade 0.1% (2/3460); cardiac perforation 0.03% (1/3460); and endocarditis 0.03% (1/3460). For more details, refer to the sources of evidence (see Appendix). 2.4.2 The Specialist Advisors listed arrhythmias, stroke, device embolisation and cardiac tamponade as potential adverse effects of the procedure.

There is the potential for long-term adverse effects and clinicians should report these to the Medicines and Healthcare products Regulatory Agency (MHRA).

These recommendations were based on evidence on the use of Amplatzer®, CardioSEAL®, STARFlex® and Helex® devices for the endovascular closure of atrial septal defect. The Institute may review the procedure if further data relating to other devices become available.

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

• Interventional procedure overview of endovascular closure of atrial septal defect, March, 2003

Available from: www.nice.org.uk/ip146overview